Attrition mill or disintegrator



Aug. 18, 1942. T. D. sHANKEl. 2,293,667

ATTRITION MILL QR D ISINTEGRATOR Filed Feb. 19, 1940 A 5MP/fw' PatentedYAug. 18, 1942 UNITED STATES PATENT oFFIcE ATTRITION MILL R DISINTEGRATORrllimothy D. Shankel, Bristol, Tenn. Application February 19, 1940,Serial No. 319,797

4 Claims.

This invention relates to improvements in an attrition mill ordisintegrator for reducing middling stock in flour mills to flour andparticularly to reducing the finer middlings and flakes in their lastreduction in the process of milling whereby a closer yield and softer,whiter flour is produced.

More specifically the invention relates to the construction of adisintegrator head with a revolving disk so constructed and arrangedthat exact and desirable adjustment may be had, thus reducing thegrinding friction, giving a more even grind of the material, with lesspower consumption than is possible of structures of a similar type.

One of the objects of the invention is to provide a disintegrator headof such a construction that a choking of the stock is substantialyeliminated or materially minimized whereby production with the use ofthe device is increased.

.Another object of the invention is to provide a disintegrator head withan adjustable structure that can be so regulated that the our part ofthe middling is reduced to a finer state while the bran part of thestock is not broken up as finely as with other types of devices utilizedfor the same purpose.

- Another object of the invention is to provide a structure for thepurpose specified in which direct grinding action is eliminated.

A still further object is to provide a device for the purpose specifiedin the form of an attachment which will fit the conventional Buckleymiddling mill as an attachment without material changes or alterations.

Other objects will more clearly hereinafter appear by reference to theaccompanying drawing forming a part of the specification and whereinlike characters of reference designate corresponding parts throughoutthe several views in which:

Fig. 1 is a vertical section view.

Fig. 2 is an end elevational.

Fig. 3 is an enlarged section showing the revolving grinding disk.

The present assembly includes a base A and standards B and C, the formerbeing the supporting element for the mill structure and the latter beingthe frame element for supporting with a central opening D through whichthe drive shaft d extends. A hopper F is provided at the inlet endthrough which material is fed to the mill and this material is movedforward by means of the feed screw or auger G mounted on the enclosedend of the shaft d. The screw feed G terminates inward of the flange eproviding a chamber g between the same and the adjacent face of thedisintegrator or attrition structure hereinafter mentioned. A pulley I-Iis mounted on the end of the shaft d outward of the support C forconnection with a suitable source of power. Any driving means may beutilized which is convenient and suitable for the work to beaccomplished. Secured to the front flange e of the mill housing E is thedisintegrator casing which, includes front wall J, the connecting innerwall 7', and side walls 7". The inner or connecting wall, 7 is formedwith an opening K at a point in axial alignment with the screw feed G.The portion; of the wall i which defines the opening K ccn-y stitutes aportion of one of the walls forming the chamber y at the end of the feedscrew G. The face of the wall :i which faces the end of the screw feed Gis beveled at an oblique angle, as shown at lc. This bevelled face lcand the chamber g form in connection with the attrition disk L the mainfeatures of the structure. The attrition disk L is mounted to freelyrotate with the shaft l, the latter rotating in the hub portion l'against the thrust bearing M. The inner race m is supported on thereduced extremity of the shaft Z and cooperates with the race m toprovide for the mounting of the balls therebetween as shown. The outerrace bears against the transverse bar N which latter provides theadjustable backing element for the thrust action of the rod l carryingthe disk L. The thrust bar N is mounted on the spaced fixed pins O, theinner ends of which o are threaded into the outer wall J of the millstructure. The thrust bar N against which the bearing M operates isformed with spaced openings through which the fixed pins O extend. Theouter end of the pins. O are threaded to receive the adjusting wheelsy Pwhich by virtue of the compression springs p exert an adjusting thruston the bar N and thus, against the grinding disk L whereby this grindingdisk L is adjusted with respect to the adjacent face of the inner wall7" of the disintegrator hous` ing. The upper end of the disintegratorcasing, defined by the walls J, i and :1" is provided with an openingand a suitable closure cap Q to permit access to the interior thereof.

Y The feed augerG is arranged for longitudinal.

sliding adjustment within the cylindrical casing E and with the shaft d,whereby the Width of the compartment y may be regulated in a manner toobtain a desirable feeding of the material and regulated disintegrationis obtained. The adjustment of the auger G is obtained by means of theset collar R, the latter being slidably arranged on the shaft d andsecured with relation thereto and with respect to the bearing r by meansof the usual set screw r as illustrated. Instead of the auger G beingfixed to the shaft d and adjusted through the sliding movement of theshaft in its bearings, as shown and described, the auger might bearranged to slide on the shaft and in this manner regulate the size oftheattrition chamber g.

In the operation of the apparatus forming the subject-matter of thepresent invention the auger G is first set in the feed cylinder E' tospace the same properly with respect to the wall :i whereby the size ofthe chamber g is properly determined for use with the type of auger andAits R. P. M. This adjustment is made by means of the set collar Rslidably arranged on the shaft d and cooperating with the shaft .bearingr atgthe upper end of the standard G. The adjustment of the auger toprovide the chamber g is of utmost importance. The auger is normallydriven at approximately 400 R. P. M. and forces the stock into the smallchamber g at the left end of the feed cylinder E. The rotation of theauger further causes the stock to be carried around in the samedirection it is turning and this in turn causes the disk L to revolveinY the same direction and with the stock. The relative rotation of thedisk L with respect to the R..P. M. of the auger is determined by theadjustment of the hand Wheels P-P, the best results being obtainedV bydriving the auger at a speed approximately ten times faster than the R.P. M. of the disk L. The width of the chamber g is such as to preventany direct grinding action of the material. Instead, the stock is forcedinto the small attrition chamber g and is turned by theauger, The stockadjacent the auger is carried around rapidly due to the rotation of theauger while the stock next to the head is being carried aroundproportionately much slower. Consequently the stock is disintegratedinto very ne flour which passes out between the disk L and the adjacentwall. The thrust on the disk L is transmitted. to the shaft l and thenceto the thrust bearing M, and associated parts t the adjacent Wheels'P-P. The rotary action imparted to the disk L and its curved face bothfunction to keep a constant discharge through the opening and preventsclogging of the disintegrated stock. This clear'- ance -between the diskL and they adjacent wall y", as previously stated, is regulated by thehand wheels P-P and determines the flneness to which the stock is to bedisintegrated or reduced before passing out into the opening. It will benoted that the working face of the disk L is slightly rounded and thisrounded face of the disk and the bevelled inner face of the feed openingK are essential to a successful fricticnalgrinding action of thematerial and discharge thereof as above set forth.

It will thus be seen that the adjustment of the auger G with its driveshaft will determine the sizeof the chamber g, This adjustment isproportional to the size and R. P. M. of the auger. The disintegrationof the stock in the chamber g is further determined bythe adjustment ofthe disk L, arranged at the discharge opening of the chamber y by meansof the hand wheels P-P and the associated parts. The discharge of thematerial is facilitated and packing of the stock eliminated by thebevelled inner face lc of the wall 1i' adjacent the feed opening K andthe rounded cooperating face of the freely rotating disk L.

What I claim as new and desire to secure by Letters Patent is:

1. In an attrition mill, a cylindrical feed chamber formed with an inletand having an open discharge end, rotary feed means for moving materialfrom the inlet toward the open discharge end to form an attritionchamber, said feed means being adjustably positioned in said feedchamber andterminating at a point spaced from the open discharge end, asecond chamber attached to said feed chamber formed with a feed openingrestricting the discharge end of said feed chamber, the outer face ofthe wall of said second chamber defining the feed opening forming theouter wall of an attrition chamber defined at its opposite end by Saidfeed means, said outer face portion being bevelled toward the dischargeopening, a shaft supported .in a bearing in a Wall of the secondchamber, said shaft being in axial alignment with the feed opening andbeing longitudinally adjustable to position one end adjacent the feedopening, a rotatable disk on said shaft end adjacent the feed opening,said disk having a slightly curved Working face, a thrust bearing at theopposite end of said shaft, a thrust bar opposed to said bearing, guidepins fixed to said second casing and extending through said thrust barat each side of said thrust bearing, the outer ends of said pins beingthreaded to engage threaded openings formed in hand Wheels, and springmeans interposed' between the hand wheels and thrust bar for resistingthe thrust transmitted from the feed means.

2. In a grinding mill assembly, a support, a cylindrical feed chambermounted on said support and having an inlet and an open discharge end,an auger of less length than the feed chamber positioned therein, adrive shaft for said auger, means for adjusting said auger in said feedchamber to provide a chamber at theV discharge end of said feed chamberof a predetermined size, a disintegrator casing positioned Yadjacent thedischarge end of the feed chamber, -said disintegrator casing having oneof its Walls formed with a discharge opening centrally positioned withrespect to the discharge end of the feed chamber and restricting thesize of said discharge, a freely rotatable disk positioned in thedisintegrator casing at the discharge opening and in axial alignmentwith said auger to normally oppose the passage of material through saidopening in opposition to its movement under action of said auger, themarginal face of said disk being bevelled at an acute angle With respectto the plane of the adjacent Wall face, a support for said disk,resilient means urging said disk towards the restricted opening, andmeans for adjusting said resilient means.

3. In a grinding mill assembly, a support, a cylindrical feed chambermounted on said support and having an inlet and an open discharge end,an auger of less length than the feed chamber positioned therein, adrive shaft for said auger, means for adjusting said auger in said feedchamber to provide avvariable chamber at the discharge end of said feedchamber, a disintegrator casing positioned adjacentthe discharge end ofthe feed chamber, said disintegrator casing having one of its wallsformed with a discharge opening centrally positioned with respect to thedischarge end of the feed chamber and restricting the size of thedischarge opening, the face of said Wall within said feed chamber anddefining the discharge opening being bevelled towards said opening at anacute angle, a freely rotatable disk positioned in the disintegratorcasing at said discharge opening, said disk face being curved away fromsaid discharge opening, whereby there is provided a restricted outlet toand from which the movement of the material is facilitated, and meansfor adjustably and resiliently urging said disk towards said restrictedopening.

4. In a grinding rnill assembly including a cylindrical feed chamberhaving an intake and an open discharge end, a separable disintegratorchamber, one wall of said disintegrator chamber forming the closure forthe discharge end of said feed chamber, said closure end wall beingformed with a discharge opening of a diameter materially less than thediameter of said feed chamber, a feed screw having one end arrangedunder said intake and its opposite end terminating in spaced relation tosaid discharge opening to form a material accumulating chamber, theinner face of the Wall of said disintegrator chamber adjacent saiddischarge opening being bevelled at an acute angle with respect to theplane of the adjacent wall face, a freely revoluble disk arrangedadjacent said discharge opening in said separable disintegrator chamber,said disk having slightly curved edges adjacent the Wall defining saidopening which curved edges overlap the Wall dening the dischargeopening, and said disk, discharge opening and auger each being arrangedwith a common axis.

TIMOTHY D. SHANKEL.

